Bacteriostasis Of Photovalent Ion Titanium On Phytophthora Infestans And Field Control Of Potato Late Blight

Potato is an important food crop in the world.Late blight causes enormous economic losses to all potato planting industries in the world,and China is a big potato planting country.For a long time,researchers at home and abroad have explored potato late blight and its prevention and control measures in many ways.Chemical control is still the most effective measure to deal with potato late blight.However,chemical pesticides seriously pollute the environment and endanger human and animal health,so it is particularly important to choose environmentally friendly pesticides.Photovalent ion titanium?TIVL?is environmentally friendly and harmless to humans and livestock,and can effectively reduce the incidence of crop diseases and alleviate symptoms.Based on the study of bacteriostasis mechanism of photovalent ion titanium?TIVL?,this study explored the effects of different concentrations of photovalent ion titanium on mycelial growth,zoospore release and germination of Phytophthora infestans and their pathogenicity through laboratory experiments;analyzed the sensitivity of different strains to metalaxyl and TIVL;and applied TIVL and chemical agents to field control of late blight of potatoes.In order to provide theoretical and experimental basis for the popularization and application of TIVL in the control of potato late blight,and to provide a new way for reducing the application of chemical pesticides,increasing efficiency and environmental protection.Through the above research,the following results are obtained:1.Antibacterial effect of TIVLTIVL inhibited mycelial growth,zoospores and zoospores germination and pathogenicity of Phytophthora infestans,and was positively correlated with the concentration of TIVL.The average inhibition rate of 16?g/mL TIVL on mycelial growth of Phytophthora infestans was 95.77%.The average inhibition rate of 16?g/mL TIVL on zoospore release of Phytophthora infestans was 99.07%.The average inhibition rate of 32?g/mL TIVL on zoospore germination of Phytophthora infestans was 92.73%.The average inhibition rate of 32?g/mL TIVL on pathogenicity of Phytophthora infestans was 91.11%.The biological characteristics of Phytophthora infestans were significantly different from those of the control group at 0?g/mL.2.Sensitivity of different strains to metalaxyl and TIVLTwo target strains?10 strains in total?were randomly selected from five provinces and municipalities,and their EC₅₀0 and RI values for metalaxyl and TIVL were determined respectively.No cross resistance of target strains to metalaxyl and TIVL was found.3.Control Effect and Yield Change of Potato Late Blight by Mixed Combination of TIVL and ChemicalsThe control effect and yield of potato late blight were improved by using titanium-containing agents and traditional agents in the field.The average control effect of using titanium-containing agents alone was only 40.66%and the increase rate was 13.9%.However,the average control effect of Titanium-containing agent Taigule mixed with 68%Jingmetalaxyl-Manganese-Zinc WDG was 77.15%,and the increase rate was 44.39%.